1. Field of the Invention
This invention relates to a method for describing the structure of a robot configured to command or control movement of a robot using a CPU, a robot device and a part of a robot.
2. Description of the Related Art
Many of robots are assembled to a pre-set shape by combining plural parts in a predetermined correlation and the various parts are driving-controlled to change the posture or movements.
For example, a robot disclosed in Japanese laying-Open Patent H-5-245784 is configured to be constructed to a desired shape by combining plural articulated modules and plural arm modules. This robot is configured so that a proper number is set for each articulated modules and a controller recognizes the connection sequence of each articulated module based on the proper number obtained by communication with each articulated module such that a control program can be rewritten to a suitable one based on this recognition.
There is also known a computer game in which a virtual robot or a virtual animal is moved on a computer by computer graphics (CG) and the behavior of the virtual robot or the virtual animal is changed responsive to the input information by a sensor connected to the computer.
There is also stated in many textbooks for robots a method for calculating the movement of a real robot in which, in doing simulation of the real robot, a model having the same shape and weight mass as those of the real robot is constructed on a computer and a force physically present in real world, such as the force of gravity, is applied thereto to find its movement by calculations.
Meanwhile, the robot disclosed in Japanese laying-Open patent H-5-245784 is presupposed on a manipulator and hence cannot cope with a structure in which parts are branched into two or more portions nor with the control which parts is based on the input information from various sensors. Thus, the present Assignee has proposed in Japanese laying-Open Patent H-9-19040 a robot apparatus made up of plural components, in which there are provided first storage means for storing the shape information for determining the shape of the parts, second storage means for storing the movement information required for describing movement of parts, third storage means for storing the information on characteristics of electronic parts housed in the parts and detection means for detecting the state of the respective parts. This robot apparatus also has control means capable of automatically recognizing the overall structure or movement characteristics of the parts based on the results of detection by detection means. In this robot apparatus, each storage means of each part is configured to store a conversion program used for converting first data represented by the predetermined data format set in common for each function of the electronic parts into second data represented by the data format used for each function of each electronic part by a control program used by control means for controlling the parts. The result is that each part can be designed without dependency on the data format pre-set by the control program.
By storing the shape or the function information in the robot parts and combining these parts by an information line system (serial bus) configured for allowing recognition of the sequence, it is possible for the CPU controlling the robot to know the robot shape, types and the mounting sites of the sensor and the actuator.
In the Japanese Laying-Open patent H-9-19040, there is realized a robot of one of a number of configurations having one of a variety of configurations of the mechanical system which automatically constructs a software object managing the information owned by robot components termed a virtual robot and the connection sequence from the information owned by the serial bus and the robot components for driving-controlling the robot and which controls the robot by a common control system using a command not dependent on the mechanical system.
It is an object of the present invention to provide a robot structure describing method for representing parts of a robot apparatus as an assembly of elementary structures basically consisting in the skeletonic representation.
It is another object of the present invention to provide a robot apparatus capable of operating as a robot having various functions of a structure represented by an assembly of elementary structures basically consisting in the skeletonic representation.
In one aspect, the present invention provides a method for describing a structure of a robot including resolving a robot part CPCi into J elementary structures PARTj, and specifying the structure of the robot by the connection information CONNECTi and the shape information jSHAPEi made up of a vector jpi and a transformation matrix jRi. This allows representation of a robot structure by a set of elementary structures which is based on a skeletonic representation.
Preferably, the initial coordinate point of the next part is given by the terminal point of a connection plane of the part.
With the method for describing the robot structure of the present invention, the connection information CONNECTi, vector jpi and the transformation matrix jRi can be set rather freely. Even complex parts having various functions can be represented by defining that the functions exist at the beginning or end points of the vector jpi.
In another aspect, the present invention provides a robot apparatus including overall control means, and a plurality of parts CPC containing electronic parts including an actuator and/or a sensor for measuring a pre-set physical quantity, the overall control means doing overall recognition and control by the shape information for determining the shape of the part, the motion information necessary for stating the motion of the part, the information on characteristics of the electronic parts housed in the parts, and the connection information specifying the connection status of the parts, wherein parts CPCi are composed of J elementary structures PARTj and the connection information thereof, the connection information is CONNECTi, the shape information of the elementary structures PARTj is jSHAPEi, the dynamic information of the elementary structures PARTj is jDYNi and the functional information of the elementary structures PARTj is jFUNCi, and wherein the connecting information CONNECTi is represented by a symbol xe2x80x9c-xe2x80x9d specifying serial connection to a previous elementary structure and a symbol xe2x80x9c;nxe2x80x9d specifying connection to the elementary structure n elementary structures before, the shape information jSHAPEi is represented by a vector jpi of a straight line and the coordinate transformation to the next elementary structure at an end point of iPARTj is given by the transformation matrix jRi, the dynamic information jDYNi is comprised of a vector jsi to the center of mass jGi of iPARTj represented by the coordinate system jxcexa3i of iPARTj, an inertia matrix jIi, centered about mass jmi, jGi and the information jai which gives the direction of motion at the beginning point of iPARTj, in which the torque and the direction in which is generated the function positioned at the beginning point is accorded by the function information jFUNCi of the elementary structures PARTj, the functional information jFUNCi is the connection information specifying the connection state of parts. By the overall control means doing overall recognition and control, the robot device can operate as a robot having various functions and also having a structure represented as a set of elementary structures which is based on skeletonic representation.
The robot part according to the present invention includes storage means for storing the information on physical characteristics of parts, and means for retrieving the information stored in the storage means.